The present invention uses electro hydrodynamic (EHD) forces to generate coaxial jets and to stretch them out to the desired sizes. For appropriate operating conditions, a liquid flow rate, in the form of a micro/nanometric-sized jet, is issued from the vertex of a Taylor cone (i.e., a liquid meniscus which adopts a conical shape due to the balance between the electric stresses and the interfacial tension). For appropriate operating conditions, a liquid flow rate, in the form of a micro/nanometric jet, is issued from the vertex of such a Taylor cone. The break up of this jet gives rise to an aerosol of charged droplets, which is called electrospray. This configuration is widely known as electrospray in the cone-jet mode (Cloupeau et al., J. Electrostatics, 22, 135-159, 1992). The scaling laws for the emitted current and the droplet size of the electrospray are given in the literature (see, e.g., Fernández de la Mora et al., J. Fluid Mech., 260, 155-184, 1994; Gañán-Calvo et al., J. Aerosol Sci., 28, 249-275, 1997; Gañán-Calvo, Phys. Rev. Lett., 79, 217-220, 1997; Hartman et al., J. Aerosol Sci., 30, 823-849, 1999). Electrospray is a technique which has satisfactory proved its ability to generate steady liquid jets and monodisperse aerosols with sizes ranging from a few of nanometers to hundred of microns (Loscertales et al., J. Chem. Phys., 103, 5041-5060,1995). Generally, in most electrospray experiments, a unique liquid (or solution) forms the Taylor cone. However, the procedure described in the U.S. Pat. No. 5,122,670 (Jun. 16, 1992) and U.S. Pat. No. 5,517,260 (Oct. 20, 1992), entitled “Multilayer Flow Electrospray Ion Source Using Improved Sheath Liquid” and “Method and Apparatus for Focusing Ions in Viscous Flow Jet Expansion Region of an Electrospray Apparatus,” respectively, involve two or more miscible liquids which were properly injected to be mixed in the Taylor cone to improve the transmission of ions, and the stability and sensitivity of a mass spectrometer. Other patents of interest to the present invention relating to electrospray technology include, for example, U.S. Pat. No. 4,885,076 (Dec. 5, 1989), U.S. Pat. No. 4,977,785 (Dec. 18, 1990), U.S. Pat. No. 5,170,053 (Dec. 8, 1992), U.S. Pat. No. 5,171,990 (Dec. 15, 1992), U.S. Pat. No. 5,393,975 (Feb. 28, 1995), and Re. 35,413 (Dec. 31, 1996).
Recently there has been significant interest in providing food products having increased health and/or nutritional benefits. Such improved food products and/or such functional foods generally have one or more added ingredients which are included to provide a specific health and/or nutritional benefit. Thus, food such as breads with added carbohydrates, cereals with added vitamins and/or minerals, foods in which undesirable components are reduced by the addition of other more desirable components (e.g., replacement of fat with a fat substitute), soy protein-containing foods, fiber-containing foods, protein-enriched foods, omega fatty acid-containing foods, calcium or other mineral or vitamin enriched foods, dietary supplement-containing foods, and the like are becoming increasing popular with a health conscious public. Such improved or functional foods may contribute to overall well being and/or reduce the risk of certain diseases or conditions.
Unfortunately, it is often difficult to incorporate such ingredients in food products without adversely affecting the organoleptic and/or other properties of the food product. Ideally, it desired to provide such an improved or functional food product which has taste, texture, and other organoleptic properties as close to, and perhaps even superior to, the conventional food product without the added ingredients. In many cases, however, such additives provide undesirable flavor, aroma, textural, or similar properties to the foods to which they are added. In some cases, the enhancing additives may even react or complex with other components of the food product (including, for example, other desired enhancing additives) thereby adversely affecting the food product in some manner or making the additives less readily available for absorption and use in the body upon consumption.
Thus, it would be desirable to provide improved and/or functional foods wherein such enhancing additives are contained in a form which prevents or significantly reduces impairment of the organoleptic or other properties of the foods to which they are added. The present invention provides such improved and/or functional foods. For example, the present invention allows for the incorporation of enhancing additives which would, except for the use of the present invention, normally result in taste, aroma, textural, or other organoleptic defects when added to food products. Thus, the present invention allows for the product of improved and/or functional foods without, or with significantly reduced, organoleptic defects normally associated with such enhancing additives; indeed, the improved and/or functional foods of this invention closely mimic the corresponding conventional food without such enhancing additives.